Work shaping apparatus

ABSTRACT

The work, an array of blanks, is formed as determined by a cam. The blanks are clamped and are rotated in engagement with a rotating grinding wheel coaxially with the cam; the cam is rotated in engagement with a rotating cam follower. The assembly including the work and cam is suspended from a heavy rigid rocker support which is pivoted about a flexible pivot in accordance with the contour of the cam as the cam is displaced laterally by the cam follower. The flexible pivot includes a plurality of pairs of crossed flexible strips, each pair anchored in a pair of blocks at an angle to each other. The strips are displaced from each other edgewise and if they engage at all, engage at centers of their edges which do not move. The strips extend, and are capable of flexing, between the blocks. The intersections of the planes defined by the pairs of strips when unflexed, define a common line which is the axis of the flexible pivot. One of the blocks of each pair is secured firmly to a rigid support and the other block of each pair to the rocker support. The rocker support and the blocks connected to this support rock about the axis defined by the strips. The strips are capable of flexing over a very small angle but the work is clamped at the end of the rocker support remotely from the axis so that the displacement of the work and cam is amplified and is substantial. To take up the weight of the rocker support and flexible pivots the frame and pivots are suspended from a torsion bar which is coaxial with the axis of the flexible pivot. The motor for rotating the work is mounted on the fixed support and drives the work through timing belts.

United States Patent Armitage 1 July 1, 1975 WORK SHAPING APPARATUS rotating cam follower. The assembly including the [76] Inventor: Harry J. Armitage, 1546 Cavitt Rd., work and a i sfspended from a hefivy rigid F Monroevme Pa. 15146 support which is pivoted about a flexible pivot in accordance with the contour of the cam as the cam is Filedi 1973 displaced laterally by the cam follower. The flexible 211 App1.No.: 409,314

[52] US. Cl 51/101 R [51] Int. Cl B24b 9/14 [58] Field of Search 51/101 R, 101 LU [56] References Cited UNITED STATES PATENTS 2,132,949 10/1938 Green 51/101 R 2,191,898 2/1940 Nelson... 51/101 R 2,334,938 11/1943 Lang 51/101 R 2,415,062 1/1947 Green 51/101 R 2,460,744 2/1949 Green 51/101 R 3,449,866 6/1969 Suddarth 51/101 R 3,513,598 5/1970 Asselin et a1 51/101 R Primary ExaminerOthell M. Simpson Attorney, Agent, or Firm--Wymen Diamond [5 7] ABSTRACT The work, an array of blanks, is formed as determined by a cam. The blanks are clamped and are rotated in engagement with a rotating grinding wheel coaxially with the cam; the cam is rotated in engagement with a pivot includes a plurality of pairs of crossed flexible strips, each pair anchored in a pair of blocks at an angle to each other. The strips are displaced from each other edgewise and if they engage at all, engage at centers of their edges which do not move. The strips extend, and are capable of flexing, between the blocks. The intersections of the planes defined by the pairs of strips when unflexed, define a common line which is the axis of the flexible pivot. One of the blocks of each pair is secured firmly to a rigid support and the other block of each pair to the rocker support. The rocker support and the blocks connected to this support rock about the axis defined by the strips. The strips are capable of flexing over a very small angle but the work is clamped at the end of the rocker support remotely from the axis so that the displacement of the work and cam is amplified and is substantial. To take up the weight of the rocker support and flexible pivots the frame and pivots are suspended from a torsion bar which is coaxial with the axis of the flexible pivot. The motor for rotating the work is mounted on the fixed support and drives the work through timing belts.

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CONTROL I CLAMP WORK CONTROLII CONTROLIII CONTROL 1! CONTROL 1' WORK SHAPING APPARATUS BACKGROUND OF THE INVENTION This invention relates to work forming or work shaping in the practice of which work blanks, typically of tungsten carbide or the like, are ground to a predetermined contour. This invention has particular relationship to such work forming in which grinding is con trolled by a cam which causes the grinding wheel and the work to move towards and away from each other so that the desired contour of the work is produced autornatically. Typical of the teachings of the prior art relating to work forming or shaping of this type are US. Pat. Nos. 2,786,312, 2,932,133, and 3,027,693 to Harry J. Armitage. While the grinding apparatus disclosed in these patents has performed exceptionally well, it has the disadvantage that after it is in use for some time, its precision deteriorates and the work processed, usually tungsten carbide bits, does not have the precise form demanded by industry.

It is an object of this invention to overcome this disadvantage of the prior art and to provide work forming and shaping apparatus whose precision shall not material-1y deteriorate in use and in whose prolonged use precisely shaped work shall be produced.

SUMMARY OF THE INVENTION In apparatus of the prior art the movement of the work relative to the grinding wheel is effected by bearing parts which move relative to each other in contact with each other. Typically in Armitage 312 the cradle 3-l (FIG. 1) rocks on ball bearing assemblies 141-153 and 145-157. It has been realized that the deterioration of the precision results from the wear of these bearing parts which move in contact with each other. The wear is abnormal because the forces between the grinding wheel, which is usually a diamond wheels, and the work, which is usually of tungsten carbide or the like, are very high; the reactive forces on the bearings are then very high and wear down the bearing parts in the area of the moving contact.

In accordance with this invention there is provided workshaping apparatus of the camcontrolled type in which the pivot for, or the axis of, the rocking supporting structure, which is called rocker support and which produces the cam-controlled relative movement of the work and grinding wheel, includes no relatively moving .parts in contact with each other during the grinding.

The rocker is mounted on a flexible or resilient pivot formed of crossed flexible strips which may be out of contact with each other or may engage edgewise only at the centers about which the strips flex. The line defined by the intersection of the planes of the strips constitutes the axis about which the rocker rocks.

An object of this invention is to provide a flexible pivot which is uniquely suitable to be integrated in the above-described work-shaping apparatus but also has general applicability.

In accordance with an aspect of this invention a flexible pivot is provided which includes a pair of resilient members and a pair of blocks. Each resilient member is of generally I-shape but with long wide rigid ends and a short very-thin central flexible web. The members are anchored edgewise at an angle to each other in the blocks with the ends secured to the blocks. The blocks are spaced a short distance apart and the flexible webs or strips extend freely between the blocks and can flex.

The line defined by the intersection of the planes defined by the strips constitutes the axis of the pivot.

In the practice of this invention a plurality of flexible pivots are mounted, between a fixed support and the rocker support, with their axes colinear. One block of each pivot is connected rigidly to the fixed support and the other to the rocker support. Under the mtrol of the cam, the rocker support rocks about the axis of the array of pivots moving the blocks to which it is connected relative to the blocks connected to the fixed support and flexing the strips. The flexing of the strips is limited to a' small angle by the blocks which are spaced a very small distance but the components which are being rocked are suspended from the rocker support at a substantial distance from the pivot axis and are capable of being rocked with a substantial amplitude.

In the general practice of this invention any of the three components involved in the shaping; the grinding wheel, the work and the cam, or the cam follower, may be rocked while the others rotate about fixed axes. In the embodiment of this invention specifically described herein the work and cam are rocked while the grinding wheel and cam follower rotate on fixed axes. To the extent that this invention may be practiced by rocking other components than the work and cam, such practice is within the scope of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of this invention, both as to its organization and as to its method of operation, to gether with additional objects and advantages thereof, reference is made to the following description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a view in side elevation of apparatus according to this invention;

FIG. 1A is a view generally diagrammatic showing the manner in which constant pressure is impressed against the action of the flexing pivot of the apparatus shown in FIG. 1;

FIG. 2 is a fragmental view in side elevation showing the relationship of the work, grinding wheel, cam, and cam follower;

FIG. 3 is a plan view, with a fragmentary part broken away and sectioned, of the part of the apparatus shown in FIG. 1 including the work-clamping means and its pivotal support including the flexing or resilient pivot;

FIG. 4 is a view in section taken along line IV-IV of FIG. 3;

FIG. 5 is a view in section taken along line VV of FIG. 3;

FIG. 6 is a view in end elevation of the part of the apparatus shown in FIG. 3;

FIG. 7 is a view in side elevation of a resilient or flexing pivot in accordance with this invention;

FIG. 8 is a plan view of one of the blocks of the pivot shown in FIG. 7;

FIG. 9 is a view in section taken along line IX-IX of FIG. 8;

FIG. 10 is a view in end elevation of the block shown in FIGS. 7, 8 and 9;

FIG. 1 l is a plan view ofa resilient or flexing member of the pivot shown in FIG. 7;

FIG. 12 is a view in side elevation of this flexing member;

FIG. 12A is an isometric view of a split pin used to secure the flexing member to the blocks in the flexing pivot according to this invention;

FIGS. 13, 14, 15. 15A. 16, 17 are similar to FIGS. 7 through 12 but show the dimensions of a typical flexing pivot used in the practice of this invention;

FIG. 18 is a plan view of the grinding wheel support of the apparatus shown in FIG. 1;

FIG. 19 is a view taken along line XIX-XIX of FIG. 18;

FIG. 20 is a view in end elevation of the part of the apparatus shown in FIG. 19;

FIG. 21 is a view in section taken along line XXI- -XXI of FIG. 22 showing the mechanism for moving the grinding wheel and its support by precise increments during a grinding operation;

FIG. 22 is a view in section taken along line XXII- XXII of FIG. 21;

FIG. 23 is a view in section taken along line XXIII- XXIII of FIG. 21;

FIG. 24 is a plan view of the cam follower assembly of the apparatus shown in FIG. 1;

FIG. 25 is a view in section taken along line XXV-XXV of FIG. 24;

FIG. 26 is a view in section taken along line XXVI- XXVI of FIG. 24;

FIG. 27 is a view in end elevation of the assembly shown in FIG. 24; and

FIG. 28 is a block diagram showing the manner in which the apparatus according to this invention is controlled during a grinding operation.

FIGS. 13 through 17 are presented solely for the purpose of aiding those skilled in the art in practicing this invention and not with any intention of in any way limiting this invention.

DETAILED DESCRIPTION OF EMBODIMENT The apparatus shown in the drawings includes a work-clamping assembly 31 (FIG. 1), a flexible suspension 33 (FIG. 4) for the work-clamping assembly 31, a grinding-wheel assembly 35 (FIGS. 1 and 18), a feed 36 (FIG. 23) for the grinding wheel, and a cam follower assembly 37 (FIG. I). This apparatus is mounted on the table 39 of the machine base 40 having a supporting plate 41 on leveling pads 43. The machine base 40 has an enclosure 45 with access doors 47 for electrical and hydraulic parts.

The work-clamping assembly 31 includes a headstock 51 (FIGS; 1 and 4) and a tail-stock 53 both driven through pulleys 55 and 57 (FIG. 4) respectively. In FIGS. 1 and 4 the head-stock 51 and tail-stock 53 are shown retracted. The head-stock 51 includes a spindle 59 having a center 61. The center 61 is secured centrally to the spindle 59 by bolt 63 (FIG. 4). This spindle 59 may be described as the cam shaft as the cam 65 is secured to a shoulder on this shaft and is rotatable therewith. The cam shaft 59 is rotatable on roller bearings 67 and 69 (FIG. 4) in a housing 71 and on thrust roller bearings 73 between the housing 71 and a shoulder on the shaft 59. Oil seals 75 are provided between the shaft 59 and the housing 71. A seal 76 is also provided to prevent the penetration of particles from the grinding operation and other matter into the rotating parts. i

A brake 77 is provided for preventing abrupt movement over regions of small radius of the cam 65. This brake 77 includes a disk brake 79 secured to housing 71 which'is engaged by a plate brake 80. The plate brake 80 and disk brake 79 are urged into engagement by a lock-nut 83 and lock-washer 85, the washer being secured adjustably in key-slot 87.

The tail-stock (FIGS. 1 and 4) includes a spindle 91 having a center 93 which is rotatable in roller bearings 95 in a sleeve 97. The sleeve 97 and spindle 91 also carry cooperative thrust roller bearings 99. The spindle 91 and the sleeve 97 and their bearings 95 and 99 are moveable downwardly or upwardly by hydraulically actuable piston 101 so that the work 103 (FIG. 2) may be clamped between the head-stock 51 and the tail-stock 53, or the head-stock and tail-stock retracted. The fluid pressure for clamping is supplied through conductor 105 (FIG. 1) into cavity 107 (FIG. 4) and for retracting through conductor 109 (FIG. 1) into cavity 111. During the clamping back pressure supplies fluid through fitting 113 (FIGS. 1, 3 and 4) and channel 115 (FIG. 1) into cavities 116 (FIG. 3) to lock the tail-stock 53 in the clamping position and prevents movement of the tail-stock generally perpendicularly to its axis. The back pressure moves pistons 118 inwardly against the action of spring 120. The pistons l 18 engage and clamp sleeve 97. The spindle 91 is driven by a splined shaft 117 (FIG. 4) rotated in bearings 119 by pulley 57. O- ring seals 121 are provided between piston 101 and a sleeve 123 in which splined shaft 117 is rotated and between piston 101 and a sleeve 125 in housing 126 to prevent penetration of the hydraulic fluid. Set screw 128 in keyway 130 prevents rotation of sleeve 97. The center 93 is shielded from debris by a bellows 127 which is connected to the sleeve 97 at its moveable rim and to the guard 129 (FIG. 1) for the tail-stock 53 at the fixed end.

In the usual practice of this invention the work is clamped vertically. This orientation of the work has the advantage that it facilitates automatic handling of the work since the blanks need only be stacked by a stacking facility. In addition, work of substantial length, for example a long stack of blanks, when supported vertically does not sag under gravity as it would when supported horizontally. It is emphasized that the vertical orientation of the work secured between the headstock 51 and the tail-stock 53, rather than supported from a center (for example magnetic center) is unique. So supported the work is not displaced by the large forces which are impressed during the grinding operatron.

' The flexible or rocker suspension 33 (FIG. '4)-for the work-clamping assembly 31 (FIG. 4) includes a rigid massive fixed support 131, a rigid massive rocker support 133 and flexible or resilient connecting assembly 135 for suspending the rocker support 133 from the fixed support 131. The connecting assembly 135 serves as a flexing pivot about which the rocker support 133 rocks.

The fixed support 131 includes an angle plate having a base 137 (FIG. 6) secured to the table 39 and a vertical plate 139. The vertical plate 139 is strengthened by gussets 141 between which a strengthening plate 143 (FIG. 6) extends.

The rocker support 133 includes a pair of plates 145 and 147 to which strengthening cross plates 149 and diagonal plates 151 are welded to form a rigid massive structure.

The flexible or resilient suspension 135 (FIG. 4) includes a plurality of flexible pivots 153 and a torsion rod 155. Each flexible pivot 153 (FIGS. 7-12) includes a pair of blocks 157 and 159. Each block 157, 159 has a face 161 abutting its supporting structure and an opposite face 163 of substantially smaller area. The face 163 has a groove 165 at the center into which slots 167 open. The groove 165 and the slots 167 extend along the whole width of each block. The slots 167 (that is, their center lines and sides) are at equal angles to the center plane between the faces 161 and 163. The slanting faces 169 are penetrated by holes 171 which open into the respective slots 167. The face 161 of each block 157, 159 is slightly concave (FIGS. 9 and to give a pinching action by the blocks 157 and 159 on the flexing members 173 and 174 in the slots 167.

Each flexible pivot 153 also includes a pair of flexible or. resilient members 173 and 174. Each member 173 and 174 is of generally I cross-section with long rigid ends 175 of substantial thickness and a thin flexible web 177. The ends are penetrated by holes 179. Typically the members 173 and 174 are composed of a high-strength steel, for example maraging steel.

The members 173 and 174 are secured in the coextensive slots 167 of the blocks 157 and 159, one flush with the faces 131 on one side and the other flush with the faces on the opposite side, with the webs 177 extending into the grooves 165. In FIGS. 7-12, member 173 is shown flush with the face 181 in the drawing and member 174 flush with the opposite face. The members 173-174 are securely held in the blocks 157 and 159 by pins 160 which are firmly secured in holes 171 and 179 and by the pinching action of the blocks.

Block 157 of each flexible or resilient pivot'153 is secured to the plate 139 (FIGS. 4 and 6) of the fixed support 135 by bolts 185 and 186 (FIGS. 4, 6) and pins 187, eachof the latter passing through coextensive openings 189 (FIGS. 7-12) in the blocks 157 and in the plate 139. Bolt 186 when secured in thread 188 pulls the concave surface 161 outwardly distorting block 157 and producing a pinching action on the members 173, 174. Block 159 of each flexible pivot 153 is secured to plate 145 of the rocker support 133 by bolts 191 and by pins 193. The head-stock 51 and the tailstock 53 are secured to plate 147 of the rocker support 133 by bolts 195 and 197 which are screwed into bosses 199 and 201 respectively of the housings 71 and 126 respectively and pass through bosses 203 and 205 respectively of plate 147. w.

The weight of the rocker support 133 and the parts connected to it including the head-stock 51 and the tail-stock 53, which is substantial and would tend to distort the flexible pivots 153, is taken up by the torsion rod 155. The rod 155 is secured to a bracket 207 welded to the plate 139 and suspends the rocker support 133 and its parts from another bracket 209 secured at one end to the rod 155 and at the other to the t The flexing pivots 153 and the rod 155 are mounted with their axes colinear. The rocker support 133 and the parts secured to it are capable of flexing about the common axis of the pivots 153 and rod 155, the webs 177 flexing and the rod twisting in torsion in accordance with the flexing of the rocker support 133. Since the surfaces 163 of each flexing pivot 153 are spaced only a small distance (typically 0.0185 inch) the angle over which the webs 177 and the rod 155 can twist is relatively small and is well within the proportional limit of the webs and rod. The head-stock 51 and tail-stock 53 are suspended a substantial distance from the axis and are moveable over a substantial distance with the rocker support.

The head-stock 51 and tail-stock 53 are rotated through the pulleys 55 and 57 (FIG. 4) from a motor 211 (FIG. 5) mounted in the enclosure of the machine base 40. The motor 211 drives a shaft 213 through reduction belt drive 215. The shaft 213 is rotatable in bearings 219, 221, 223 (FIG. 4). The bearings 219 are mounted in a sleeve 224 (FIG. 5) in table 39 engaging a shoulder on shaft 213. The bearings 221 are mounted in a boss 225 (FIGS. 4, 6) of bracket 227 secured to base 137', the bearings 223 are mounted in a boss 229 of an angle bracket 231 secured to plate 139.

The head-stock 51 is rotated by a belt drive including belts 233, 235 (FIG. 4), pulley 237 on shaft 213, pulleys 239 and 241 approximately coaxial with the axis 243 of the flexing pivot 135, and the pulley 55. The tailstock 53 is rotated by a belt drive including belts 245 and 247, pulley 249' on shaft 213, pulleys 251 and 253 approximately coaxial with the axis 243 and the pulley 57. Belts 233 and 245 are maintained tight by idler pulleys 255 and 257 respectively. Pulley 255 is adjustably mounted on bracket 259 and pulley 257 on bracket 261. The belts, 233, 235, 245, 247 are timing belts having teeth which mesh with the teeth in pulleys 237, 239, 241, and 249, 251, 253, 57. Since the motor 211 is mounted on a plate in enclosure 45 (FIG. 5) the rocker support 133 is relieved of carrying the weight of the motor. The pulleys 239, 241 and 251, 253 are approximately centered on the axis 243 so that the drive is not affected by the rocking of the rocker support 133.

The grinding wheel assembly 35 (FIGS. 1 and 18-20) includes the grinding wheel 271 which is secured to shaft 273 driven by motor 275. Shaft 273 is rotatable in roller bearings 277 and is provided with thrust needle bearings 279 which operate against races 280. The motor 275 is mounted on, and the bearings 277 are mounted in, slide 283. Slide 283 is actuable by pistons 285 (FIG. 20) in cylinders 287 to slide upwardly or downwardly on ways289 and 290 in wheel-head housing 291 and carries with it the motor 275, shaft 27 3 and grinding wheel 271. A gib 292 is interposed between way 290 and slide 283. Dogs 293 and 295 are adjustably mounted in a T-slot 296 which is carried with the slide 283. Dog 293 actuates limit switch lLS and dog 295 limit switch 2L5 which are mounted on the wheelhead housing 283.

The wheel-head housing 291 is pivotally mounted in horizontal *slide 301 on pins 303 (FIG. 20) and is pivotal or tiltable over a limited angle so that the grinding wheel 271 may be set at an angle to the work. The angle of tilt is set by handwheel 305. The handwheel 305 carries an adjusting screw having an unthreaded tip 309 which is rotatably secured to the cross-member 311 of a clevis or trunnion 313 between washers 315 one of which engages the shoulder of the screw from which the tip 309 extends and also the cross member 311, and the other of which is engaged by a ring retainer 317 in a groove in the tip 309. Between its legs the clevis carries a pivoting pin 319 pivotal in a bearing block 321. The clevis 313 is thus pivotally suspended from a block 321 secured to wheel-head housing 291. A tye-bar 322 is pivotally mounted between the vertical walls 323 of horizontal slide 291 on pins 325. The screw 307 engages the tye-bar 322. The screw is provided with a cover 327 (typically an elasticon cover). Rotation of tilting handwheel 305 is so that the outer end of the screw 307 moves outwardly tilts the wheelhead housing and the grinding wheel 271 counterclockwise; rotation of the handwheel 305 so that the outer end moves inwardly tilts the wheel-head housing clockwise.

For locking the wheel-head housing 291 in an angular position locking screws or threaded pins 331 (FIGS. 1, 18, 20) are provided in each wall 323. The screws 331 extend through slots 333 in the walls and engage threaded holes (not shown) in the wheel-head housing 291. Each locking screw 331 is secured in any position by a handle 335. In selected discrete positions, typically at intervals of the wheel-head housing is also secured by locating pins 337 which pass through holes 339 in walls 323 and engage holes (not shown) in wheel-head housing 291. The wheel-head housing 291 may also be secured by locking screw 331 in intermediate positions. A scale 332 and pointer 334 are provided to indicate the angular position of the wheel-head housing 291 in degrees. To facilitate the tilting a space 336 is provided between the wheel-head housing 291 and the horizontal slide 301.

The horizontal'slide 301 is slideable away from and towards the work 103 on ways 341 and 342 (FIGS. 1 and 21, 23) extending from a support 343 secured to table 39. By moving the horizontal slide the grinding wheel 271 may be moved towards and away from the work 103 at a low measured time rate and it may also be moved into grinding position or out of grinding position rapidly. The latter movement is called rapid traverse. The movement is accomplished by the wheelhead feed 36 (FIGS. 21, 22, 23) which is contained in effected by the drive shown in FIGS. 21, 22, 23. This drive includes a hydraulic motor 351 suspended from gear box 353 secured to the rim of an opening in table 355 of support 343. On the shaft 357 of the motor 351 there is an index plate or detent disk 359 and a spur wheel-head feed housing 352. The slow movement is gear or pinion 361 which are rotatable together. The

disk 359 includes detents 363 at precise intervals which are selectively engageable by a stop-pin 364 slideable in bushing 366 by a plunger 365 in cylinder 367. The plunger 365 may be set to actuate pin 364 to engage in detent 363 after the disk 359 has been rotated through a preselected number of detents. The pinion 361 drives a shaft 371 through a spur gear 373 at reduced speed. Shaft 371 drives another shaft 375 at further reduced speed through gears 376 and 378. Shaft 375 carries a worm 377 which drives a worm wheel 379 rotating shaft 381. Shaft 381 drives ball screw 383 whose thread meshes with ball nut 385. Ball nut 385 engages feed-bar 387. Ball screw 383 is rotatably supported by its stem 389 in common with shaft 381 on bearings 391 and on bearings 393 in horizontal slide extension 395. The connection between stem 389 and shaft 381 is a splined connection so that ball screw 383 and its stem 389 can slide relative to shaft 381.

The rapid traverse is effected hydraulically by operation of piston 401 in cylinder 403. In FIG. 21 piston 401 is shown in the retracted position with the grinding wheel 271 retracted from the work 103. Piston 401 is secured to feed-bar 387. The movement of piston 401 under the action of cylinder 403 inwardly or outwardly moves feed-bar 387, the horizontal slide 301, and the grinding wheel 271 correspondingly. The stem 389 slides in the spline in shaft 381. Feed-bar 387 carries a dog 407 (FIG. 21) which in the extreme positions of the piston 401 actuates limit switch 3LS or limit switch 41.5.

The grinding wheel 271 may be driven towards and away from the work 103 manually through the worm 377 and worm wheel 379 by a hand-wheel 411. The hand-wheel 411 is freely rotatable on a shaft 413 and may be connected to the shaft 413 by a coupling 415 (FIG. 23). The coupling 415 has teeth 417 which can be meshed with teeth in the end of a boss 419 on the hand-wheel 411 when the hand-wheel is pressed inwardly against the action of spring 421. The coupling 415 is keyed to the shaft 413 at key-slot 423.

Shaft 413 carries, at its end, a bevel gear 425 which meshes with bevel gear 427 on shaft 375 that carries worm 377. When the hand-wheel 411 is pressed inwardly, so that the teeth 417 are engaged, and turned, ball screw 383 is rotated in ball nut 385 and horizontal slide 301 is advanced or retracted to advance or retract grinding wheel 271. Hand-wheel 411 has a scale (not shown). A pointer 431 (FIG. 21) is provided adjacent the wheel 411 to correlate the position of wheel 411 and the grinding wheel 271.

A limit switch SLS (FIG. 21) is provided in wheelhead feed housing 352 adjacent the wheel 411. This limit switch SLS is actuated when the wheel is pressed inwardly relaxingthe fluid pressure on motor 351 and permitting rotation of shaft 375.

The cam-follower assembly 37 (FIGS. 2427) includes a cam follower 441. The cam-follower 441 is an integral part of shaft 443 in cam-follower-bearing housing 445 rotatable on roller bearings 447 and ball bearings 449. Housing 445 is mounted on guides 451 whose ends are secured (pressed into) housing 445. The guides 451 are slideable in cam-follower support housing 453; lubricant is injected into the grooves 455 of guides 451 to facilitate the sliding movement. The camfollower support housing 453 is secured by bolts 457 and pins 459 to the table 39.

The cam-follower bearing housing.445 is suspended from the guides 451 and may be moved towards and away from the cam 65 (FIG. 2) by rotation of camfollower adjusting screw 461 (FIG. 25). The screw 461 is journaled in flanged bearings 463 and is held in the housing 453 by retainer ring 465. The guides 451 may be locked in any position by guide clamps 467 (FIG. 26). Each clamp 467 includes a pair of coaxial spaced bars 468 (FIG. 26) which are engaged by a screw 469. The threads of the bars 468 are such that when the screw 469 is turned the bars 468 move in opposite directions. Each pair of bars 468 engage their associated guide 451 in coextensive arcuate grooves 471 (FIG. 26). When the screw 469 is turned so that the bars 468 move towards each other the guide 451 is clamped. 4

In the practice of this invention the cam 65 is urged into engagementwith the cam follower 441 by a pressure-applying assembly 481. This assembly 48.1 (FIG. 1A) applies compressed air pressure which is maintained constant. The'assembly 481 includes an air cylinder 501 which is" supplied from a compressed air reservoir 503 through conductor 505. The reservoir 503 is of large volume (typically 1000 times) compared to the volume of the cylinder 501. A piston (not shown) is operated by the air in cylinder 501 and urges piston rod 507 outwardly so that its swiveled head 509 engages the housing 71 (FIG. 4) to urge the cam 65 and cam follower 271 into engagement under constant pressure.

At the start of an operation the head-stock 51 and tail-stock 53 are centered. For this purpose the centering pin 487 is inserted in an opening in the cam shaft 63 and turned with handle 489 so that its pin 491 locks in groove 493 (bayonet lock). The pressure is then reduced in cylinder 501 and the cam 65 disengaged from the follower 441 and the head-stock 51 and tail-stock 53 are turned with a centering gauge (not shown) against the head-stock center 61. If the gauge does not remain at for a 360 turn, adjustment is necessary.

Next the pin 487 is unlocked from the shaft 59 and the pressure applying assembly 481 is set to apply pressure to the head-stock 51 and between the cam 65 and cam follower 441. The head-stock is now rotated through 360 with the centering gauge against the head-stock center 61. The screw 461 (FIG. 25) is now adjusted so that the maximum excursions of the headstock center 61 about the lowest innermost and highest outermost positions are equal.

The operation of the apparatus will be described with reference to FIG. 28. Controls I, II, III, IV and V in FIG. 28 are presented separately for convenience in explaining the operation. In the typical practice of this invention these Controls I through V will be included in a single control unit.

It may be assumed that at the start of an operation the grinding wheel 271 is retracted and switch 5L8 is actuated. Handwheel 305 is operated to set the grindingwheel 271 at a predetermined angle to the work 103. Now Control I is actuated to cause fluid to flow through conductor 105 to clamp the work 103. Control V now actuates cylinder 403 to move the grinding wheel 271 to grinding position. Actuation of switch SLS is interrupted and switch 4LS is actuated. This enables Control II to actuate cylinders 287 to reciprocate the grinding wheel 271 upwardly and downwardly. At the end of the upward movement switch lLS is actuated enabling Control III to cause motor 351 to advance the grinding wheel 271 towards the work 103 a predetermined precise preselected distance measured by the number of detents 363 in disk 359 (FIGS. 21, 22). When this number is counted out Control III actuates cylinder 365 to snap shot pin 364 into the last detent. At this point Control II actuates cylinders 287 to move the grinding wheel downwardly. Switch 11.8 is deactuated and at the end of the down traverse switch 2LS is actuated further advancing the grinding wheel '271 towards the work 103. This process is repeated feasible This invention is not to be restricted except insofar as is necessitated by the spirit of the prior art.

I claim:

1. Apparatus for shaping work including a cam for determining the final shape of said work, flexible pivot means including at least one member having a resilient web from which arms extend oppositely, said web being flexible to permit one of said arms to pivot relative to the other, said flexible pivot means defining a first axis of said web about which said one arm is pivotal relative to said other, a rocker support connected to said one arm pivotal back and forth with said one arm about said axis as a center, clamping means for said work rotatable about a second axis and connected to said support pivotal therewith, means mounting said cam rotatable about said second axis with said work, a cam follower rotatable in engagement with said cam and pivoting said cam and said work in accordance with the shape of said cam, and grinding means in grinding engagement with said work as said work is pivoted and rotated to shape said work.

2. Apparatus for shaping work including a fixed support, spring means having opposite ends and defining between said ends an axis about which one of said ends is pivotal relative to the other, a rocker support, means suspending said rocker support from said one end pivotal therewith about said axis relative to said other end of said spring means, means for suspending said other end from said fixed support a cam shaped to determine the final shape of said work, means connecting said cam to said rocker support to pivot said rocker support relative to said other end of said spring means, through pivotal cycles in accordance with the point-by-point shape of said cam, grinding means for said work connectable in grinding engagement with said work, and means connected to said rocker support, responsive to the shape of said cam, for controlling the positioning of said work relative to said grinding means while said grinding means is in grinding engagement with said work to shape said work as governed by said cam.

3. Apparatus for shaping work including a flexiblepivot means defining an axis about which said flexible pivot means is pivotal, said flexible pivot means including at least a pair of resilient strips, each strip flexible in a plane transverse to its ends and said flexible pivot means also including means mounting said strips with said plane of one of said strips at an angle to said plane of said other of said strips so that the intersection of said planes defines said flexing axis, a fixed support, a rocker support, means connecting the ends of said strips on one side of said axis to said fixed support and the ends of said strips on the opposite side of said axis to said rocker support, so that said rocker support is pivotal relative to said fixed support about said axis, a cam shaped to determine the final shape of said work, means connecting said cam to said rocker support to pivot said rocker support through pivotal cycles in ac cordance with the point-bypoint shape of said cam, grinding means for said work connectable in grinding engagement with said work, and means, connected to said rocker support, responsive to the shape of said cam, for controlling the positioning of said work relative to said grinding means while said grinding means is in grinding engagement with said work to shape said work as governed by said cam.

4. The apparatus of claim 2 wherein the spring means is constructed so that the one end of the spring means is pivotal relative to the other end over a small angle of 

1. Apparatus for shaping work including a cam for determining the final shape of said work, flexible pivot means including at least one member having a resilient web from which arms extend oppositely, said web being flexible to permit one of said arms to pivot relative to the other, said flexible pivot means defining a first axis of said web about which said one arm is pivotal relative to said other, a rocker support connected to said one arm pivotal back and forth with said one arm about said axis as a center, clamping means for said work rotatable about a second axis and connected to said support pivotal therewith, means mounting said cam rotatable about said second axis with said work, a cam follower rotatable in engagement with said cam and pivoting said cam and said work in accordance with the shape of said cam, and grinding means in grinding engagement with said work as said work is pivoted and rotated to shape said work.
 2. Apparatus for shaping work including a fixed support, spring means having opposite ends and defining between said ends an axis about which one of said ends is pivotal relative to the other, a rocker support, means suspending said rocker support from said one end pivotal therewith about said axis relative to said other end of said spring means, means for suspending said other end from said fixed support a cam shaped to determine the final shape of said work, means connecting said cam to said rocker support to pivot said rocker support relative to said other end of said spring means, through pivotal cycles in accordance with the point-by-point shape of said cam, grinding means for said work connectable in grinding engagement with said work, and means connected to said rocker support, responsive to the shape of said cam, for controlling the positioning of said work relative to said grinding means while said grinding means is in grinding engagement with said work to shape said work as governed by said cam.
 3. Apparatus for shaping work including a flexible-pivot means defining an axis about which said flexible pivot means is pivotal, said flexible pivot means including at least a pair of resilient strips, each strip flexible in a plane transverse to its ends and said flexible pivot means also including means mounting said strips with said plane of one of said strips at an angle to said plane of said other of said strips so that the intersection of said planes defines said flexing axis, a fixed support, a rocker support, means connecting the ends of said strips on one side of said axis to said fixed support and the ends of said strips on the opposite side of said axis to said rocker support, so that said rocker support is pivotal relative to said fixed support about said axis, a cam shaped to determine the final shape of said work, means connecting said cam to said rocker support to pivot said rocker support through pivotal cycles in accordance with the point-by-point shape of said cam, grinding means for said work connectable in grinding engagement with said work, and means, connected to said rocker support, responsive to the shape of said cam, for controlling the positioning of saId work relative to said grinding means while said grinding means is in grinding engagement with said work to shape said work as governed by said cam.
 4. The apparatus of claim 2 wherein the spring means is constructed so that the one end of the spring means is pivotal relative to the other end over a small angle of about 1* and the controlling means is connected to the rocker support in a region remote from the region to which the rocker support is connected to said one end so that the movement impressed by said rocker support on the controlling means is substantially amplified.
 5. The apparatus of claim 3 wherein the flexible pivot means includes a torsion rod connected to the fixed support and to the rocker support and vertically supporting the weight of said rocker support, the controlling means and the strips and their mounting means and preventing the torque exerted by said rocker support and controlling means on said strips from deforming said strips, the axis of torsion of said rod being coextensive with the axis defined by said strips.
 6. The apparatus of claim 2 including a fixed support, and means connecting the other end of the spring means to the fixed support so that the spring means is suspended from said fixed support, the controlling means of said apparatus including means, pivotal with said rocker support, to be rotated to position the work relative to the grinding means as recited and also including a drive for rotating said means to be rotated, means mounting said drive on said fixed support, and belt and pulley means connecting said drive in driving relationship with said means to be rotated.
 7. The apparatus of claim 1 including a fixed support, the rocker support being suspended from the fixed support by the flexible pivot means, the said apparatus also including a drive for rotating the clamping means, work and cam, means mounting said drive on said fixed support, and belt means connecting said drive in driving engagement with the clamping means, work and cam.
 8. Apparatus for shaping work including means for clamping said work in position to be shaped, means, connected to said clamping means, for rotating said clamping means and said work, a grinding wheel, means connected to said grinding wheel for rotating said grinding wheel in grinding engagement with said work, the grinding surface of said grinding wheel being of substantially smaller length than the length of the surface of said work to be ground in shaping said work, means connected to said rotating means for said grinding wheel for moving said grinding surface of said wheel back and forth along substantially the whole surface-to-be-ground of said work as said grinding wheel is in grinding engagement with said work, and detent counting means, connected to said rotating means for said grinding wheel for advancing said grinding surface of said wheel towards the surface-to-be-ground of said work by predetermined incremental steps determined by the counts of said detent means at the end of each of at least certain of the back and forth movements of said grinding wheel.
 9. The apparatus of claim 2 including constant-pressure means for urging the cam into engagement with the cam follower.
 10. The apparatus of claim 9 wherein the pressure is fluid pressure and is derived from a compressed fluid reservoir through a cylinder which is of small volume compared to the volume of the reservoir.
 11. Apparatus for shaping work including a flexible pivot means defining an axis about which said flexible pivot means is pivotal, a fixed support, a rocker support, means, including said flexible pivot means flexibly suspending said rocker support from said fixed support pivotal about said axis, a cam shaped to determine the final shape of said work, means connecting said cam to said rocker support to pivot said rocker support through pivotal cycles in accordance with the point-by-point shape of said cam, grinding means for said work, connectable in grinDing engagement with said work, and means connected to said rocker support, responsive to the shape of said cam, for controlling the positioning of said work relative to said grinding means while said grinding means is in grinding engagement with said work to shape said work as governed by said cam, the said controlling means including means, pivotal with said rocker support, to be rotated to position the work relative to the grinding means, in accordance with the point-by-point shape of said cam, while said grinding means is in grinding engagement with said work, the said controlling means also including a drive, mounted on said fixed support, for rotating said means-to-be-rotated, and the said controlling means also including first pulley means, mounted on said fixed support coaxial with said axis, second pulley means connected in rotating relationship with said means-to-be-rotated, means connecting said drive to rotate said first pulley means, and a belt directly connecting said first pulley means in rotating relationship with said second pulley means. 